Best Resolution/File Format For Scanning Negatives?

I just bought the Epson Perfection 3590 Photo Scanner. It has an automatic loading tray which is nice but I'm having trouble figuring out what resolution to scan my negatives at. I've been making TIFF files, is that the best way to go? So far, I've only been expreimenting with my B&W negatives but I'll be doing color ones soon enough as well.

I want the files to be large enough and detailed enough that I might be able to make posters, 8x10 prints and web graphics out of them. Any suggestions would be appreciated, thanks.

I'm personally taking up photography (and photoshop) as a hobby but in my professional life, I just founded a scanning company... tada! I am years late to this thread and brand new to the forum but thought I'd post a reply for anyone who reads this even today...

I agree- it's important to scan at the highest resolution possible. At my scanning company we default to scan at at least 3000dpi for good resolution of negatives, and offer "professional" resolution to 6000dpi. Even if you are only scanning to "view" or store your negatives now you'll want *at least* 3000dpi for good quality. (Negatives, and especially slides, come out beautifully at 3,000dpi) Later, it's likely you'll want to print from those digital images - another reason to go as high res as possible. Also, part of the scanning process, I assume, is also to digitally archive and preserve your old negatives for years, and even generations to come. (Printed images can fade up to 50% in 20 years!) Again, you'll want to do that at as high a resolution as possible, in which case may want to consider 6000 dpi.

These days with DVDs, you'll be able to fit thousands of images onto one DVD so storage of these big files is pretty easy. Just thought I'd throw it out there! (I know some projects are really big with a lot of negatives so I'd hate to think someone would realize this later and have to go back to scan again.) Hope this helps!

Note that the DPI Sean is referring to is not the same as the PPI that is used to describe the size a digital image will print at.

Chromogenic prints made on archival paper, like Kodak's Professional Supra Endura VC Digital Paper, or Kodak's Professional Supra Endura Metallic Digital Paper don't fade in 20 years.
The standard archival value is 100 years in home display, and 200 years in dark storage.

Inkjet printing is another matter. With inkjet printing the quality of the inks/dyes/paper used is paramount. High quality, long lasting inkjet fine art prints are also known as Giclée prints.

Black and white film has more resolution than color, so lets take that to run with. One of the highest resolution films I know of (for normal pictures) is Ilford Delta 100 at 160lp/mm. This works out to about 4064 DPI, assuming you have a lens that can do that (some Zeiss glass can come close), are on a sturdy tripod, lock the mirror up or better yet, have no mirror at all, and there is no wind, no traffic for miles, no one walking within 100 feet and no planes overhead, you MIGHT could get an image that could actually resolve to that. But even in perfect conditions, with a perfect piece of Zeiss glass, with that film, you still could never ever get more resolution than 4064 DPI so anything above that in optical scanning is just wasting time and space, period. In the real world, 3000 DPI is about all you will ever need, and even that is higher than 99.9% of all images you will ever run across.

Black and white film has more resolution than color, so lets take that to run with. One of the highest resolution films I know of (for normal pictures) is Ilford Delta 100 at 160lp/mm. This works out to about 4064 DPI, assuming you have a lens that can do that (some Zeiss glass can come close), are on a sturdy tripod, lock the mirror up or better yet, have no mirror at all, and there is no wind, no traffic for miles, no one walking within 100 feet and no planes overhead, you MIGHT could get an image that could actually resolve to that. But even in perfect conditions, with a perfect piece of Zeiss glass, with that film, you still could never ever get more resolution than 4064 DPI so anything above that in optical scanning is just wasting time and space, period. In the real world, 3000 DPI is about all you will ever need, and even that is higher than 99.9% of all images you will ever run across.

Allan

Click to expand...

First - 160 lp/mm is more like 8128 spi (or ppi if you wish) because it takes a minimum of two scanner samples to resolve a line pair, not one. (lp/mm is line pairs per mm - ie one dark line and one light line)

I believe that it is worth scanning film at resolutions higher than 3000 spi if you wish to preserve the film's look when it is enlarged. The lower the scan resolution, the more the film will look digital and the less the characteristic grainy signature of the film will be preserved. You are tying to represent the real graininess of the film not grain aliasing, a scanning artifact. When printed to 24 x36 inches (ie a 24x enlargement) I notice a distinct improvement in the look of Kodachrome scanned at 8000 spi on an Imacon 949 vs a 4000 spi scan (true 3800 spi resolution) on a Nikon 5000 or 5400 spi (true 4400 spi or a little higher) on a Minolta 5400 Elite.

Many consumer scanners do not have a true scan resolution that meets their nominal optical resolution, so even a true 3000 spi is hard to acheive. They may produce the right number of pixels without interpolation, but their optics and stepper mechanics are just not up to the claimed resolution - that's why truly high resolution flatbeds weigh upwards of 70 lbs and have superb lenses.

Yes, lp/mm is line pairs per mm, unfortunately in real life it just does not work that way. Following your calculations, 160lp/mm would indeed be 8128 DPI (or spi, or ppi, or whateverPI) which would give 35mm film a resolution of (160*2=320, 320*.9948819"=7860, 320*1.417323"=10885, 7860*10885=83,596,800 pixels) 84MP which is just not realistic. Doing the same math at 160 gives you about 21MP which holds true if not in mathmatical fact, in side by side print comparisons. You are not going to get me to believe a single frame of 35mm film will be superior to an 80MP Phase One meduim format camera.

My reasoning to this has always been that I suspected film is rated in line pairs, reusing the second line to compare to the third, then the third to the fourth, and so on. While this is just my own personal theory, and I did not stay at a Holiday Inn last night, it does explain why 16x20 prints from a 35mm frame and a 20MP digital look so close in resolution of details, at least to me. YMMV.

Wow! I have experience using a screen ds2020 and scitex scanners and you guys just blow me away with your knowledge. I like the theory of scanning at a super high res to best interpret the medium you are scanning.

Ctein also did a recent, newer article on scanning at higher and higher resolutions...might be of interest to some folks. I was unaware that the folks at Scan Science made adapters that allowed wet scanning with even modest, pedestrian scanners. Wet Mounting & Fluid Scanning